People aren't sacrificing when they
aren't buying the Dining Plan just by virtue of not buying it or not doing the promotion (speaking towards your last part of the above comment).
You have to consider many things like discounted tickets you can get, hopper add on requirement, how much you really think you're going to spend on food and drink, etc. If you're only considering the cost of the dining plan if it wasn't included compared to it being included and looking at what room only discount gets you well then you really haven't done the math.
Just as an example from out 2017 trip:
~We bought discounted park hopper tickets from
UT back in 2016 but at the 2015 prices UT had
~We applied a room only discount and because Standard room was not available at that time for the promotion 'upgraded' to a Preferred room but with a savings of $83.53 from the rack rate of the Standard room already booked (a discounted Standard room rate would have been something like $200+ difference).
~We spent $55.38 (includes tax excludes tip) at Skipper Canteen (includes a dessert), $52.19 (includes tax excludes tip) at 50s Prime Time and $56.45 (includes tax excludes tip) at Mama Melrose (which was slightly higher because we each had a beer). We ordered what we wanted at those places. Now we did have water at Skipper Canteen and 50s Prime Time but we went in September it was hot and we wanted to stay hydrated. Mama Melrose we didn't have a bunch of rides or being out in the sun much after we were eating dinner.
- The approximate value of the regular Dining Plan (which gets you the 1 TS credit per day) at 2017 prices was $69.36 pp per night (ETA I know the regular Dining Plan includes snack and QS meal but it is still calculated per person costs). We had 5 days at WDW and did 3 TS meals total. You can see where it wouldn't have worked out for us at all. We spent less for 2 people than the regular Dining Plan would have allotted for 2 people (ETA: even including the QS meal and snacks other food we got throughout the day was significantly less than what would have been allotted for 2 people if we had done the Dining Plan). We didn't change our eating habits, we went to places we were geniunely interested in, and when we vacation during hot times of the year we do opt for water mostly as a health thing.
- But I know without a doubt people don't always look into menu pricing, they don't always go to WDW's website and look at all the places they may want to eat and get an idea of what you may want to eat, and if you're looking at it from a pure financial standpoint doing that stuff allows you to actually see if the Dining Plan (paid or with promotion) would actually work out for you.
- The rest of our meals were QS and still nowhere near the $48.19 that was the 2017 price of the QS dining plan.
~We would have lost a lot of money had we done the promotion not only because of the other discounts elsewhere we got but because eating wise we wouldn't have come close to the estimated $48.19 (2017 pricing) pp per day QS one.
Now things are a tad different since Disney implemented the expiration dates on park tickets that affected multi-day too so you wouldn't be able to buy park tickets as early as we would have before but still.
The free dining promotion requires you to purchase things at full-price (non-discounted room rate, non-discounted park tickets, upgrades to park hopper, restricted type of dining plan based on your resort category). Those are important aspects when looking at it from cost-savings promotions.